Oxidative Cyclization of 3-(3-Heterocycle-substituted 2-Propenoyl)tropolones
作者:Masaaki Honda、Kimiaki Imafuku
DOI:10.1246/bcsj.58.508
日期:1985.2
3-[3-(2-Furyl)-2-propenoyl]- (2a), 3-[3-(2-thienyl)-2-propenoyl]- (2b), 3-[3-(3-thienyl)-2-propenoyl]- (2c), and 3-[3-(3-pyridyl)-2-propenoyl]tropolone (2d) were prepared by the condensation of 3-acetyltropolone with the corresponding heterocyclic aldehydes. The compounds 2a–d were oxidized with selenium dioxide to afford 2-heterocycle-substituted cyclohepta[b]pyran-4,9-diones, while oxidation with both alkaline hydrogen peroxide and 2,3-dichloro-5,6-dicyano-p-benzoquinone gave 2-(heterocycle-substituted methylene)-2H-cyclohepta[b]furan-3,8-diones.